Update Data - DbContext Generator Template

Vijay Prativadi
12y
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Article

Introduction

This article demonstrates an interesting and very useful concept in Entity Framework.

Question: What is DbContext Generator?

In simple terms "It enables generation of code with a template based upon an Entity".

Step 1: Create a new web application

Step 2: Adding a new Entity Data Model Framework

Step 3: Add new DbContext template

Step 4: The complete code of WebForm1.aspx is as in the following:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="DbContextUpdateData.WebForm1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<div>

<table>

<tr>

<asp:Label ID="Label1" runat="server" Text="Update Data - DbContext Template" Font-Bold="true"

Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>

</td>

</tr>

<tr>

<td>

<asp:Label ID="Label6" runat="server" Text="Please Enter Id" Font-Size="Large" Font-Names="Verdana"

Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox4" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:Label ID="Label2" runat="server" Text="Please Enter First Name" Font-Size="Large"

Font-Names="Verdana" Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:Label ID="Label3" runat="server" Text="Please Enter Last Name" Font-Size="Large"

Font-Names="Verdana" Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:Label ID="Label4" runat="server" Text="Please Enter Age" Font-Size="Large" Font-Names="Verdana"

Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<asp:Button ID="Button1" runat="server" Text="Update" Font-Names="Verdana" Width="213px"

BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />

</td>

</tr>

<tr>

<asp:Label ID="Label5" runat="server" Font-Bold="true" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>

</td>

</tr>

</table>

</div>

</center>

</form>

</body>

</html>

Step 5: The complete code of WebForm1.aspx.cs is as in the following:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;namespace DbContextUpdateData

{

public partial class WebForm1 : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

}

protected void Button1_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text) ||string.IsNullOrEmpty(TextBox3.Text) || string.IsNullOrEmpty(TextBox4.Text))

{

Label5.Text = "Please Enter Some Data";

Label5.ForeColor = System.Drawing.Color.Red;

}

else

{

var id1 = Convert.ToInt32(TextBox4.Text);

var objEmployee = objEntities.tblEmployee.Where(a => a.EmpId == id1).FirstOrDefault();

objEmployee.FirstName = TextBox1.Text;

objEmployee.LastName = TextBox2.Text;

objEmployee.Age = int.Parse(TextBox3.Text);

objEntities.SaveChanges();

Label5.Text = "Data Updated Successfully";

Label5.ForeColor = System.Drawing.Color.Green;

TextBox1.Text = string.Empty;

TextBox2.Text = string.Empty;

TextBox3.Text = string.Empty;

TextBox4.Text = string.Empty;

}

#region Instance MembersCompanyEntities objEntities = new CompanyEntities();

#endregion
}
}

Step 6: The output of the application is as in the following:

Step 7: The updated data output of the application is as in the following:

I hope this article was useful for you.